docs: def ticker(self, currency="", **kwargs):
  		"""
  		This endpoint displays cryptocurrency ticker data in order of rank. The maximum
  		number of results per call is 100. Pagination is possible by using the
  		start and limit parameters.
  
  		GET /ticker/
  
  		Optional parameters:
  	    (int) start - return results from rank [start] and above (default is 1)
  	    (int) limit - return a maximum of [limit] results (default is 100; max is 100)
  	    (string) convert - return pricing info in terms of another currency.
  	    Valid fiat currency values are: "AUD", "BRL", "CAD", "CHF", "CLP", "CNY", "CZK",
  	    "DKK", "EUR", "GBP", "HKD", "HUF", "IDR", "ILS", "INR", "JPY", "KRW", "MXN",
  	    "MYR", "NOK", "NZD", "PHP", "PKR", "PLN", "RUB", "SEK", "SGD", "THB", "TRY",
  	    "TWD", "ZAR"
  	    Valid cryptocurrency values are: "BTC", "ETH" "XRP", "LTC", and "BCH"
  
  		GET /ticker/{id}
  
  		Optional parameters:
  		(string) convert - return pricing info in terms of another currency.
      	Valid fiat currency values are: "AUD", "BRL", "CAD", "CHF", "CLP", "CNY", "CZK",
      	"DKK", "EUR", "GBP", "HKD", "HUF", "IDR", "ILS", "INR", "JPY", "KRW", "MXN",
      	"MYR", "NOK", "NZD", "PHP", "PKR", "PLN", "RUB", "SEK", "SGD", "THB", "TRY",
      	"TWD", "ZAR"
      	Valid cryptocurrency values are: "BTC", "ETH" "XRP", "LTC", and "BCH"
  		"""
  
  		params = {}
  		params.update(kwargs)
  
  		# see https://github.com/barnumbirr/coinmarketcap/pull/28
  		if currency:
  			currency = str(currency) + '/'
  
  		response = self.__request('ticker/' + currency, params)
  		return response